1. Technical Field
The present invention relates to a spectrometry device and to an image forming apparatus and the like.
2. Related Art
In the related art, there is known, in an image forming apparatus such as a color printer, a device that measures the color of a color image (color patch or the like) formed by the image forming apparatus and provides feedback of a color measurement result to the image forming apparatus in order to form the color image desired by a user with high accuracy.
In such an image forming apparatus, a color image is formed on a medium such as paper and is irradiated with light from a light source, and light reflected by the color image is incident on a colorimeter to perform a colorimetry process. At this time, the colorimeter is mounted on a printer head that forms an image on the medium, and scanning with the printer head can measure the color of the color image on the medium with a simple configuration. However, driving error of the printer head, distortion of a medium transport path, strain on the paper medium, and the like change the distance between the medium and the colorimeter, and the position of measurement performed by the colorimeter may be shifted from the original position at which the color is to be measured.
Regarding this matter, there is known a device that corrects the color measurement result according to the distance between the medium and the colorimeter (for example, refer to JP-A-2010-210456).
The device disclosed in JP-A-2010-210456 irradiates the medium with light by using a light source in which the central portion is bright while the peripheral portion is dark and receives reflected light with a light receiver that is divided into a plurality of light receiving regions. Then, a distance signal corresponding to the distance between the medium and the colorimeter is calculated on the basis of a light reception signal of each light receiving element, and the amount of light received is corrected.
The device of the related art disclosed in JP-A-2010-210456 calculates the distance signal on the basis of the light reception signal from each light receiving element. As such, if the distance signal is calculated on the basis of the light reception signal, correction accuracy (color measurement accuracy) decreases because measurement noise affects the light reception signal, in which case a problem arises in that a spectrometry process (colorimetry process) cannot be performed with sufficient accuracy.